1. THEIR ROLE IN PROTEIN SYNTHESIS
DNA & RNA
THEIR ROLE IN PROTEIN SYNTHESIS

2. DNA – BASIC STRUCTURE Polymer of nucleotides
Deoxyribose (5 carbon sugar)
Phosphate group
Nitrogen base
Adenine
Guanine
Thymine
Cytosine
Hydrogen bonds
Double helix - two strands twisted

3. DNA – BASIC STRUCTURE Sides – alternating sugar & phosphate grps
5’ end
phosphate
3’ end
sugar
Steps – base pairs
Adenine – Thymine
Cytosine – Guanine
Connected by H-bonds

4. DNA STRUCTURE & FUNCTION
Blue prints for life
Carries an organisms genetic code
Carries instructions for making proteins:
Immunology
Metabolism
Respiration
Energy/Storage
Found in nucleus of cell

5. DNA - REPLICATION Make a copy of DNA Steps:
Occur prior to cell division
Steps:
Enzyme DNA polymerase unzips DNA
Two new “complimentary” strands built

6. RNA – BASIC STRUCTURE Single strand Uracil replaces Thymine 3 Types
Sugar – ribose
Phosphate grp
Uracil replaces Thymine
3 Types
Messenger (mRNA)
Ribosomal (rRNA)
Transfer (tRNA)

7. TRANSCRIPTION Process used to make mRNA from DNA Occurs in nucleus
RNA polymerase
Enzyme splits DNA so RNA can form
Role of mRNA
Carries directions making protein to the ribosome

8. TRANSCRIPTION Promoter TATA Box Section DNA where enzyme attaches
Repeating sequence bases – signals where transcription should begin
Immediately followed by start codon  AUG

9. TRANSCRIPTION CODONS – Terminator – stop signals
Groups 3 bases code for an amino acid
AUG – “start” codon, codes for methianine
64 different “3-letter” codes for 20 different amino acids
Terminator – stop signals
UGA, UAA, UAG

10. TRANSLATION
Assembly of amino acids at the ribosome to produce a protein
Initiation – joining of mRNA, tRNA & ribosome

11. TRANSLATION Elongation – the joining of amino acids
tRNA bring A. acids to ribosomes
Anticodons on tRNA match to codons on mRNA
Termination – production A. acid stops – no tRNA to match STOP codon

12. PROTEIN SYNTHESIS

13. PROTEIN SYNTHESIS
DNA
TAC GCT AAG ACT
MRNA
A. ACIDS
TRNA

14. POINT MUTATIONS Single base is changed – change in 1 a. acid
Silent (no change A.Acid) or result in disease

15. FRAMESHIFT MUTATION Insertion Deletion
Addition of base
Deletion
Removal of base
Both types result in change of entire amino acid sequence
Cytosine insertion on chrom. 16 believed cause Crohn’s disease